Polyphenol and glucosinolate-derived AhR modulators regulate GPR15 expression on human CD4+ T cells.

Area of Science:

• Immunology
• Gastroenterology
• Nutritional Science

Background:

• Diets rich in fruits and vegetables are linked to improved intestinal health, including in inflammatory bowel diseases (IBDs).
• The aryl hydrocarbon receptor (AhR) is a key regulator of mucosal immunity and T cell trafficking.
• AhR influences the expression of G protein-coupled receptor 15 (GPR15), a gut homing marker elevated in ulcerative colitis.

Purpose of the Study:

• To investigate whether dietary metabolites can modulate AhR activity and GPR15 expression on CD4+ T cells.
• To explore the potential mechanism by which fruit and vegetable consumption benefits intestinal homeostasis.

Main Methods:

• Screening of physiologically relevant polyphenol and glucosinolate metabolites.
• Assessing the impact of these metabolites on AhR activity.
• Measuring GPR15 expression on human CD4+ T cells.

Main Results:

• Polyphenol and glucosinolate metabolites were found to affect AhR activity.
• These metabolites also regulated GPR15 expression on human CD4+ T cells.
• The regulation of GPR15 expression was dependent on AhR activity.

Conclusions:

• Dietary polyphenol and glucosinolate metabolites can modulate GPR15 expression on human CD4+ T cells via an AhR-dependent pathway.
• This finding provides a potential molecular mechanism for the gut health benefits of diets rich in fruits and vegetables.